R26 battery capacity 12V

Begonnen von bwprice100, 03 Februar 2009, 18:35:49

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bwprice100

Hi All

Can anybody suggest the battery amp hour capacity for a 12V system on an R26?

Cheers Brian

bwprice100



rolf.soler

The more the better  ;D, or: as big as you can fit
I would think anything above 8 Ah is o.K., better 12 or so.
It does not really depend whether you have 12 V or 6 V. But I guess you like stronger bulbs (60/55W) if you have 12 V, therefore the battery capacity should also be higher than the (4)-6-8 Ah you have usually with 6 V systems. Depends also on the alternator: what power does it have ? (how many W). Is it a 12-V-DC alternator or a (3-phase)-AC alternator with AC/DC converter  ? (those have much more power)

† Knut

Hi Brian,

since 2 years my R27 is running with a MZ-B ignition and generator, which spends around 100 watts at higher speeds. I've chosen a battery capacity of 5Ah, since it fits very well and is a cheap one from Louis (big motocycle parts store in Germany). Never had an empty battery.


Hope it helps

Knut

Rütz

Hi Brian,

a 6V 8Ah battery is equivalent to 12V 4Ah battery and will have nearly the same size (with 12V your consumers need just half the current).

So even Knut's 5Ah battery is bigger and more powerfull than original.
A 12V 8Ah battery would only fit in the sidecar, i think.

Rütz
I never dared to be radical when young.
For fear it would make me conservative when old. (Robert Frost)

rolf.soler

Zitat von: Rütz am 03 Februar 2009, 23:35:43
Hi Brian,

a 6V 8Ah battery is equivalent to 12V 4Ah battery and will have nearly the same size (with 12V your consumers need just half the current).

So even Knut's 5Ah battery is bigger and more powerfull than original.
A 12V 8Ah battery would only fit in the sidecar, i think.

Rütz
You are right !
...but...when you have 12 V, then "your consumers" are usually replaced by more consuming ones  :)...namely the 35 W headlight bulb by a 60/55 Halogen H4-bulb. Thats the whole point of having 12 V...good strong lights...
Lets calculate: headlight: 55 + 5 + 2 + 2 + 1,2 W, taillight 5+5 W, coil 5-10W = around 80-90 W + intermittent brakelight 21 W (+ indicator lights 2x21 W)
So if you have a lot of stop and go traffic with idling / slow running machine, the battery has to deliver the 80 W whenever RPM are below 1200, that is 6,5 Amps. at 12 V. When you are above 2000 RPM, with 100W generator power, the battery is charged with about 1-2 Amps. only. So you have to drive 80% of the time > 2000 RPM to keep the battery charged. If you do, then there is no problem even with a 2 Ah battery...If not, a bigger battery does of course not solve the problem of negative bilance; you just have more reserve - recharge battery (or make a longer trip..) every 6 wks instead of 3 weeks for instance. For a Winterfahrer like me who drives every day to + from the city in morning + evening traffic,  I think the 5 Ah battery would get empty every few weeks. For the summertime overland cruiser  :) its absolutely sufficient.
So I think it is always clever to put in the biggest possible battery that fits in the provided space...a 12V battery of same Ah is not double the size of a 6 V, and its not double the price.
@ Rütz, my sidecar bike has a 12 V 28 Ah  battery  ;D (o.k. 27 Ah of it are needed for the starter...)

bwprice100

Hi All and thanks for the response.

This is a follow on from the post by 'Ziggy Kroatien' and the Chinese generator.
I have decided to look at this route and I think I have found a suitable unit. At the moment I don't have too much information on it but it will charge a 12V 9ah battery. I am not planning on putting extra electrical stuff on the bike apart from brighter bulbs so I think this might be OK.

Brian

rolf.soler

o.k.
Personally, I would not replace the good old Bosch generator by a Chinese one...The R26 generator is relatively powerful (60/90W) - compared to to the admittedly weak 45/60 generator of R25, R25/2.
You can buy 35/35 W H4 halogen bulbs with reflector units for the 6 V electrical system, relatively cheap (<50 Euro) and they are almost as bright as 12 V 60/55 W bulbs, certainly much better than the normal 35/35 bulbs.
If the original 6 V generator went bad beyond repair, I would put in a 6V replacement (same as original)  OR a MZ-B 12 V generator + ignition.
Not a Chinese scooter generator. There are still major quality problems with chinese parts, and usually they do not deliver as much as they claim....If it says 100 W on the label, it produces probably less power than your 6V generator...
It is just that we do not contradict Ziggy, because he goes ahead anyway with what he wants  ;D

bwprice100

Zitat von: rolf.soler am 04 Februar 2009, 10:27:43
o.k.
Personally, I would not replace the good old Bosch generator by a Chinese one...The R26 generator is relatively powerful (60/90W) - compared to to the admittedly weak 45/60 generator of R25, R25/2.
You can buy 35/35 W H4 halogen bulbs with reflector units for the 6 V electrical system, relatively cheap (<50 Euro) and they are almost as bright as 12 V 60/55 W bulbs, certainly much better than the normal 35/35 bulbs.
If the original 6 V generator went bad beyond repair, I would put in a 6V replacement (same as original)  OR a MZ-B 12 V generator + ignition.
Not a Chinese scooter generator. There are still major quality problems with chinese parts, and usually they do not deliver as much as they claim....If it says 100 W on the label, it produces probably less power than your 6V generator...
It is just that we do not contradict Ziggy, because he goes ahead anyway with what he wants  ;D

Hi Rolf

The problem is, I have only the bits shown and a non functioning rotor and I would say that they are not worth repairing.
The next issue is cost; the Chinese system is, in total (generator, regulator, CDI unit, coil and battery) will come in about £150 compared with over £400 for just the MZ-B system on its own and I hate to think what a genuine new Bosch system would cost me. I do however have to make a few mechanical bits and pieces in order to mount the bits.
I have looked at good second-hand BMW generators but I am concerned about 50 year old electrics. I run a 1981 R80 and all the problems I get with it now are mainly electrical and this is only 27 years old; also I would probably pay more than £150 for all the charging and ignition bits.
With regard to the capacity the system seems to check out on paper and from people who have Chinese bikes with this system on it. It has all the usual electrical items including electric start. It is a 125 cc 4-stroke single cylinder bike.
With regard to quality; I worked for Robert Bosch for nearly 8 years at there alternator plant in Cardiff; so it would probably be worth starting a separate thread on this one. :box: Bosch is still better than Lucas though. :)

Brian

Rütz

Zitat..a 12V battery of same Ah is not double the size of a 6 V..
Veto.  :box2: ;D
It surely is double the size!
With same "Ah" the single cells have inevitably the same dimensions in both batteries. But the 12V needs the double amount of cells. By a thinner design of the casing it may become a "tick" less than double.
Rütz
I never dared to be radical when young.
For fear it would make me conservative when old. (Robert Frost)

mekgyver

Hi Folks,
look always at the Energy, which a batterie (chargable akku!) is able to give.
A 12V Batterie with 10Ah Capacity has a energie about 120Wh.
The Value to compare Energie is Ws, or Work*Time  :oberlehrer:
A 6V Batterie with 10Ah Capacity has a Energie about 60Wh. -> half stored enegie vs the 12V-Version.

An example : my old '62-Opel-Olympia-Rekord-P2-Caravan 1700ccm (can be ordered! ... 9500 EUR ) has a batterie 6V/66Ah.
First i thought : wow  :o a rather big one, but compared with a 12V System : not really big for a 1700ccm engine  :P, but it works  8)

Greets, mek  :schrauber:
... 73er-Gang

rolf

Hallo Brian,
do you have the rotor (Anker)? Rewinding cost's roundabout 100€
Stator (Feldwicklungen)ok? easy to measure (?)!
Then buy a electronic regulator (Zofia or anything else): 40€
Together, original and longliving: 140 €
Rolf

bwprice100

Zitat von: rolf am 05 Februar 2009, 09:45:04
Hallo Brian,
do you have the rotor (Anker)? Rewinding cost's roundabout 100€
Stator (Feldwicklungen)ok? easy to measure (?)!
Then buy a electronic regulator (Zofia or anything else): 40€
Together, original and longliving: 140 €
Rolf


Hi Rolf

I have the Anker and the Feldwicklungen but both will need rewinding; could you recommend anybody to do this?
Regulator, I have the original but broken and parts missing.

On the ignition side I have a small number of parts but most is missing and what I have is not in good condition.

When looking to repair or replace the parts you have mentioned above it does not seem to be too much money but what would be the cost of the complete ignition and charging system, for example the cost of the Chinese system is.

Stator         £25.00
Rotor         £27.00
Rectifier/regulator   £22.00
CDI         £27.00
Coil         £27.00
Battery 12V 9aH   £25.00
Miscellaneous      £25.00

Total          £178.00

I suspect that the cost of getting together a Bosch system, including sourcing second-hand parts and refurbishment would be, say £500 to £700. If it was a different bike, say a R69/S it might be worth it but with this bike I have to keep to a budget as I still have the gear box, drive shaft, wheel, frame and metal work to refurbish.
It is probably debatable whether this bike was worth restoring or splitting for spares but there is a bit of a history with this bike, which involves murder, broken hearts, con-men, battles with government departments etc. So I am determined to get it back on the road and cost is one of things that could stop me.

Brian

rolf

Hallo,
you are sur that they need rewinding ...especially the Feldwicklung?
I dont know the cost (of shipping to the Kontinent ;D)...but you can send the whole things to me and i will have a look on this...and then will tell you something about the cost ...it will be more less (?) of 500 € ...I don't know the actually exchange Euro to pound...nearly 1:1?)...I think if you have all Parts (Fliehkraftregler etc) you are by 250€ -300€(max)

rolf.soler

Hi Brian,
That is a very good offer from H.H. Rolf I.
He has probably enough parts + equipment lying around to repair your generator 3 times around. If he can not, you know it from the highest authority  ;D
The expensive parts are the rotor, the stator / housing with field coils and the advance unit (Fliehraftregler). If you have these 3, even  if they don't look so good, it can be done at a reasonable price. If all 4 field coils plus rotor have to be rewired, well then it is a bit expensive... But that is rarely the case. The regulator can be replaced by the electronic one for 40 Euro, the coil is also not expensive, and what other parts dou you mean ? There is not much more, capacitor and contact points are also cheap; what else ?
I would not worry too much about old electrics; my two 50 year old generators have never caused trouble up to now (whereas I had to replace the chinese alternator on my chinese bike after one year  ;D). If rolf can repair the old generator for 250-300 Euro, that is a very good price , better quality and original on top...
rolf: the pound is still strong... :)1 £ is 1,15 Euro; so 250-300 Euro is 220-260 £, whereas the chinese thing is 178 £.

Zitat von: bwprice100 am 05 Februar 2009, 10:48:03
but there is a bit of a history with this bike, which involves murder, broken hearts, con-men, battles with government departments etc.
We would like to hear that story one day... :)

bwprice100

Zitat von: rolf am 05 Februar 2009, 10:56:03
Hallo,
you are sur that they need rewinding ...especially the Feldwicklung?
I dont know the cost (of shipping to the Kontinent ;D)...but you can send the whole things to me and i will have a look on this...and then will tell you something about the cost ...it will be more less (?) of 500 € ...I don't know the actually exchange Euro to pound...nearly 1:1?)...I think if you have all Parts (Fliehkraftregler etc) you are by 250€ -300€(max)

Rolf
I have sent you an email
Brian

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